Function to autologin to wordpress with only username provided

I have secured admin(s) area outside of WP site, and I am listing WP users on that page (from wp_users table), but I want to add links on that page so admin can easily login as WP user without password… only based on his username/email …. so when I provide username or email – I want WP to set cookies and sessions like he is regular user…
Does such function exists ?